It just strikes me that you, and Trump, seem to completely miss the point that these other voters are completely fed up with Biden. They are votes to be had for a candidate that doesn't tell them, "I don't want your vote". Without those votes, Trump won't be reelected. I am not "anti" Trump, but he needs to pull his head out of his ass and quit driving voters away. That includes members of his own party he keeps bashing.
When those who are fully in Trump's camp follow his lead and bash those of us who aren't, it further divides the party. If you, and he, actually looked at the numbers, it's pretty obvious we need close to 100% of our own party to cast a ballot for him. Plus, we need the bigger half of the independent/non-affiliated voters as well. Without those votes, Trump doesn't see the inside of the WH again. And as others have spoken to well, the down ballot candidates with an R after their name also suffer.
I am one who will vote for whomever has the R after their name on the general ballot in November. Primaries are when you get to vote for who you like; the general election is when you must vote for the party that closest represents your own politics. We are a 2 party country, like it or not. The election is a nose count at the end of it. The party with the most noses in each house, controls all of the committees. It doesn't matter if I like a candidate personally in November; that option ends with the convention.
If it actually matters to you that we do not suffer another 4 years of Biden, especially with a D majority in both houses, then you need to pull your head out and recognize what it takes to get elected in this country. Trump needs to reign in his BS. His followers need to do the same. Both need to start cultivating the common ground and focus on not just voter retention, but new voter acquisition. That means we need those disgruntled Ds, as well as those Rs that seem to irritate you, and Trump. Wake up to political reality.